"Imagine for a moment a different kind of investigation. What sort of security failures were involved in letting a US Ambassador get killed for the first time in 30 years? Not just any country but one that has been near the forefront of the US foreign policy agenda in the last two years. Whoever did what, the President is responsible for what happens on his watch. And when an Ambassador gets killed in the field, that's a big failure by definition. Examining what's happening could and probably would lead to some embarrassing lapses. More importantly, it might lead to improvements in how we operate in the future and prevent or limit the possibility of similar tragedies."

Respectfully, I would say no--you need to go further. Your frame is still assumes the this tragedy is a "big failure" a priori, and then buys into the Washington conceit of pin the blame for the assumed "embarrassing lapses." I would argue on the contrary that Ambassador Stevens was doing what an able foreign service officer representing a confident and subtle nation should be doing--living and travelling outside the fortified compound, engaging factions in the street, personally visiting regions and power brokers outside the capital. What we had may simply have been a black swan--an irreducible tail risk that paid off by the laws of chance, giving us a really bad, tragic, awful day as a result.

A really mature investigation by a confident nation would not focus on pinning the blame for a "big failure by definition," but would ask subtle questions like:

1. What does the US gain and lose by forcing the foreign service to prioritize security vs. access and effectiveness?

2. Where do you strike a balance? Will this incident cause is to push the balance further in the direction of security?

3. Where do the foreign service professionals themselves think we should strike the balance?

4. Were there specific procedural issues or decisions that contributed to the death of Amb. Stevens, Foreign Service Officer Sean Smith, and CIA contractors Tyrone Woods and Glen Doherty, or--as I personally suspect is likely--were risks taken with forethought that were judged to be acceptable, that in retrospect still can be judged to be acceptable and necessary--though chance did not favor us on this bad day?

It goes without saying that this kind of conversation is quite impossible to have in official Washington at the moment. Maybe it never can be. But there is no reason we can't hold ourselves to a higher standard, and try to drag the level of conversation upward by example.